Switch



July 30, 1940. F. R. MEGINNISS 2,209,702

SWITCH Filed Nov. 4, 1937 A 7" TOP/V5 v 3 Claims.

Patented July 30, 1940 UNITED STATES PATENT OFFICE My invention more particularly relates to a switch of the inertia operated type. I have shown in my Patent No. 1,948,728 a switch of such type, and my present invention is an improvement over the switch there shown.

The switch illustrated in my prior patent operates very satisfactorily. With inertia operated switches such as have hitherto been constructed. however, so far as I am aware, it has been poslO sible to operate the switch accidentally in case the device embodying the switch is subjected to a shock or movement which substantially duplicates the movement to which the switch is subjected in order properly to operate the same. 15 Such accidenta1 operation has occurred principally during the transportation of flash lights with contained cells and having switches of the foregoing character and which may be subjected to a movement which nearly duplicates the move- '20 ment of the flash light which is necessary to turn on or off the switch. It has been possible, therefore, to operate the switch accidentally and if the flash light circuit is closed for any considerable length of time the battery is, of course, depleted.

25 In accordance with my present invention, the foregoing difficulty is overcome by the provision of a switch which is operated by a rotatable weight, and when the switch is embodied in a flash light, the operator subjects the flash light 3 to a quick turning movement which is suddenly arrested.

A further object of my invention is the provision of a switch of the foregoing character which is cheap and simple in construction and reliable in operation.

My invention will best be understood by reference to the accompanying drawing in which I have illustrated a preferred embodiment of my switch in a flash light, and in which 40 Fig. l is a perspective view of the switch element embodying my invention and the support therefor;

Fig. 2 is a sectional plan view of Fig. 1 enclosed in a casing;

45 Fig. 3 is an end view of the ratchet which forms a part of the switch;

Fig. 4 is a sectional view taken substantially along the line 44 of Fig. 3; and

Fig. 5 is a front elevation partially broken 5 away and in section, illustrating the switch embodied in a flash light.

Like reference characters indicate like parts throughout the drawing.

Referring to the drawing, l0 indicates generally 55 a frame on which the switch embodied in my in- (CI. Mil-10.86)

vention is mounted. In the embodiment of my invention here illustrated, the frame comprises a bracket II, generally U-shaped in form, secured at its ends by rivets [2 to a disc I3 preferably formed of insulating material, the frame being 5 preferably enclosed in a casing I4 as best shown in Fig. 2.

A shaft I5 preferably extends axially of the flash light casing and has its bearing at one end in the bracket II and at its opposite end in an 0 opening IS in the member I3. Mounted on the shaft I5 is a weight M preferably rotatable axial- 1y of the flash light casing, though not necessarily, in the form of a disc and the mass of which when rotated is suflicient to operate the switch. The weight is also preferably, though not necessarily, balanced with respect to its axis of rotation. In the form of my invention here shown, the switch comprises a ratchet I8 the body of which is formed of insulating material mounted 2 on the shaft I5 and operable by a pawl I9 which is mounted on the weight IT and engages the teeth of the ratchet I8. The pawl may be formed of resilient material or, if desired, it may be pivoted to the weight I1 and spring pressed against the ratchet.

The ratchet and associated parts are so constructed that the circuit controlled by the switch is closed by a given operation of the pawl and ratchet and opened by the succeeding operation thereof. In the form here shown a plate or disc 20 formed of good conducting material, usually metal, is mounted on the shaft I5 adjacent to the free end of the ratchet. Preferably the body of the disc 20 is of smaller diameter than that of 5 the ratchet as best indicated in Fig. 3 and is provided with outwardly extending arms 2I the ends of which are bent and extend inwardly along a tooth of the ratchet as at 22. There are half as many arms 2| as ratchet teeth so that bent conductors 22 are provided for alternate teeth of the ratchet. The free end of a conducting arm 23 engages the ratchet at the end thereof which is provided with the bent conductors 22 and is attached to the disc I3 and is provided with a conducting pin 24 extending therethrough as indicated in Fig. 2, the end of the member 24 being connected to a conducting plate 25 provided with a terminal 26.

In the embodiment of my invention illustrated, continued movement of the weight I I after ar resting the movement of the casing on which the switch is mounted is secured by providing the weight with two pins 21 and 2' extending outwardly over the bracket II and spaced something less than 180 degrees apart. A resilient member, preferably in the form of a helical spring 28, is connected at one end to the weight I! and at the other end to the bracket I I and is so biased as normally to return the pin 2'! in engagement with the bracket I! while the other pin is normally spaced therefrom. When the frame on which the switch is mounted is subjected to a rapid rotary movement which is suddently arrested, the weight I! continues its rotary movement until the pin Zll engages the bracket II, and the weight I! is then rotated by the spring 28 in the reverse direction until the pin 21 again engages the bracket H thereby restoring the parts to their initial positions.

I have shown my invention embodied in aflash light, although it is to be understood that its use is not limited thereto. In the form shown the casing of the switch is enclosed in the cylindrical casing 29 of the flash light, insulating member 30 preferably being interposed between the casing I 4 of the switch and the cylindrical casing 29. The flash light casing may be of the usual form comprising an outwardly flared head 3| threaded to the cylindrical portion of the casing as at 32 and having the usual lens retaining cap 33 at the forward end. The casing 29 of the flash light may also contain the usualdry cells 34 connected in series with electric lamp 26! as indicated in Fig. 5. I

The operation of a flash light embodying my invention is as follows: Assuming that the conducting arm 23 is in engagement with one of the ratchet teeth which is not provided with a conducting member, then the circuit is open between the ratchet I8 and the conducting arm 23. If it is desired to close the switch for the flash light, the operator grasps the casing of the flash light and imparts thereto a rapid rotary motion in the direction of movement of the ratchet and suddenly arrests such movement which is naturally accomplished by the wrist when it has reached the limit of its possible movement. The movement of the weight l1, however, continues until the pin 2' engages the bracket II. The

movement of the pawl l9 thus produced by the rotatable movement of the weight I! rotates the ratchet I 8 through the distanceof one tooth thereby bringing the bent conductor 22 into engagement with the conducting arm 23 and thereby closing the circuit from the frame It) through the shaft to the disc 20, arm 2|, bent conductor 22, conducting arm 23, pin 24, disc 25 and terminal 25. When the switch has been thus actuated, the spring 28 returns the weight to its normal position with the pin 2! in engage- 5 ment with the bracket II.

It Will be evident that the chances of the rotatable mass being subjected during transportation or in other situations to a rotary movement of the character necessary to actuate the switch is practically negligible.

While I have described my invention in its preferred embodiment it is to be understood that the words which I have used are words of description rather than of limitation and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of my invention in its broadest aspects.

What I claim is:

1. In a flash light unit, a casing of a size adapted to be grasped by the hand of a user, an

electric lamp mounted therein, and a switching element mounted in said casing and comprising a mass axially rotatable by said casing, and

means operable in response to successive rotations of said mass in the same direction for successively closing and opening the circuit of said lamp.

2. In a flash light unit, a casing of a size adapted to'be grasped by the hand of a user, an electric lamp mounted therein, and a switching element mounted in said casing and comprising a shaft extending axially thereof, a weight mounted on said shaft and rotatable therewith, and 35 means operable in response to successive rotations of said mass in the same direction for successively opening and closing the circuit of said lamp.

. 3. In a flash light unit, a casing of a size 40 mounted on said shaft and balanced with respect thereto and rotatable with respect to said casing and means operable in response to successive rotations of said mass in the same direction for-successively closing and opening the circuit of said lamp. v

FRANCIS R. MEGINNISS. 

